Prevalence of HIV infection among siblings of HIV positive children in Calabar, Nigeria

Introduction Early diagnosis and treatment of paediatric HIV is key as mortality of untreated patients is very high in the first two years of life, and reaches 80% by four years. Case finding efforts for children especially outside Prevention of mother-to-child transmission (PMTCT) is inadequate. Targeting siblings of index HIV-exposed and infected children is an important way of improving identification and enrolment into care thereby reducing paediatric mortality. The study therefore aimed to determine the prevalence of HIV infection among siblings of HIV positive children in care in Calabar. Methods This descriptive cross-sectional study was conducted among children aged six weeks to 15 years who are siblings of HIV positive children receiving care. Parental consent and child assent were obtained, the children were tested for HIV at their homes irrespective of their prior test results. Ethical clearance certificates were obtained from the health institutions. Results Siblings of 401 index patients were tested for HIV, four were positive giving a prevalence rate of 1%. Three hundred and sixty-seven 367(91.5%) had been tested previously while 34(8.5%) never had HIV test. Among the siblings who were HIV positive, 1(0.3%) was a male while 3(0.7%) were females. There were more HIV positive siblings in the 11-15 years age group. Conclusion All the four HIV positive siblings were from the lower socioeconomic class (p=0.022). The routine screening of siblings of HIV positive children should be sustained with focus on adolescents from the lower socioeconomic class. This will improve early identification and enrolment into care thereby reducing paediatric mortality.


Introduction
According to the Joint United Nations Programme on HIV/AIDS (UNAIDS) Gap report of 2012, 19 million out of the 35 million living with HIV are unaware of their sero-status. In Sub-Saharan Africa, only 48% of adults living with HIV know their status [1,2]. In Nigeria, only 35% of people living with HIV know their status [3].
These figures may be higher in children. Identifying and diagnosing children, as HIV infected is the first step in the continuum of paediatric care and treatment, yet despite the availability of lifesaving treatment, many HIV infected children are never offered any HIV diagnostic test [4]. Even in the phase of Provider Initiated Testing and Counseling (PITC), diagnosis and treatment gaps still remain a major barrier to HIV care.
Early diagnosis and treatment of paediatric HIV is key as mortality of untreated patients is very high in the first two years of life and reaches 80% by four years [5]. Paediatric antiretroviral therapy (ART) coverage is only 20.7% leaving a gap of 80% [6]. Central to provision of treatment and support to families affected by HIV is knowledge of the HIV status of all family members and linkage to appropriate prevention, treatment and care services [1]. Case finding efforts for children especially outside PMTCT is also inadequate [7]. There is a need to scale up uptake of paediatric HIV testing services beyond the provider-initiated efforts. The present strategy of waiting to test only those children presenting to health facilities often with advanced clinical disease is inadequate [8].
Testing other family members has been identified to specifically increase family diagnosis of HIV infection [9]. Targeting siblings of index HIV-exposed/infected children is an important way of improving identification and enrolment into care thereby reducing paediatric mortality [9]. The study therefore aimed to determine what proportion of siblings of HIV infected children actually infected with HIV.

Methods
This descriptive cross-sectional study was conducted from 6th A "sibling" here is defined as a child from the same biological parents as the index patient. Addresses and phone numbers were used to contact the parents /guardians and those with siblings were identified. The purpose of the study was explained to each parent/guardian and a convenient date and time for home visit was scheduled. Parental consent and child assent were obtained, the siblings aged 6weeks to 15years in each family were tested in their homes irrespective of the prior test result. In families with more than one child receiving HIV care, the first child on the clinic register was used as the index to reach out to other siblings. Those found to be positive and not on treatment were linked to a health facility for enrolment into treatment and care. Those who objected to home visit but consented to HIV test for their children were screened at the facility where the index patient received Anti-retroviral drugs (ARVs). Children whose parents or guardian refused consent were not denied services. Siblings of HIV positive children from both health facilities younger than six weeks or older than 15 years and children whose parents or guardians declined consent were excluded from the study. Ethical Clearance Certificates were  Table   1). All the four HIV positive siblings were from the lower socioeconomic class, this was statistically significant (p=0.022).
Interestingly, all those that tested positive in the study were older than their index siblings.

Discussion
The prevalence of HIV infection among siblings of HIV positive children in Calabar was observed to be 1%. There is paucity of data on prevalence of HIV among siblings of HIV positive children.
However, the result of the current study was similar to the prevalence of 0.9% described by Ng'eno et al. [10] in a community based cross-sectional study in Kenya. The result of this study was lower than the HIV prevalence of 4.2% by Venn et al. [11] among infants attending immunization clinics. The finding of this study was also lower than the prevalence of 5.3% reported by Ntia et al. [12] in a prospective study of under-5 children admitted with diarrhea.
These hospital-based studies [11,12] were both done in the same locality (Calabar, South-south Nigeria) as the current study, suggesting a difference in the trend of HIV positivity rates in this locality between the general population and siblings of HIV positive children. The former study [11] dealt with asymptomatic children at immunization centers while the later studied symptomatic children with diarrhea and it was not surprising with the observed prevalence. The low prevalence in this study could be attributed to increased facility coverage of PMTCT in Calabar in the last few years as a lot of work has been done especially by government and nongovernmental organizations in improving access to HIV diagnosis and care.
This prevalence was much lower than the 10% reported by Ogunbosi et al. [13] in Ibadan South-west Nigeria, and the 26.9% in Brazil reported by Alberto et al. [14] The Ibadan study was hospital based as compared to this study which was community based. Furthermore, their study [13] site is a referral center and this may have contributed to the high prevalence noted. Most hospitalbased studies [15][16][17] had higher prevalence rates as they mostly target children with suggestive clinical features. The study in Brazil [14] was similar to our study, tracing siblings of HIV positive children under care. This was thought to be due to repeated MTCT. HIV is a disease that disproportionately affects those with socioeconomic status [6]. As such social inequalities may result in disparities in HIV health outcomes. Researches have suggested that a person's socioeconomic standing may affect his or her likelihood of contracting HIV and developing AIDS [19][20][21]. Our study also corroborated the above findings indicating that 100% of the siblings who turned to be HIV positive were from the lower socioeconomic status. Adejuyigbe et al. in Ife, Nigeria [22] also reported high correlation between HIV and AIDS, poverty and low maternal education.

Conclusion
The low prevalence rate of 1% observed therefore suggest that screening siblings of HIV positive children might not be very reliable channel for identification of paediatric HIV infections. In addition, focus should be on siblings from the low socioeconomic class.